In a new comedy film from Steve Coogan's Baby Cow production company, the Isle of Man is rocked by a murder, with the police bringing a fictional detective out of retirement to solve the case. Meet Mindhorn, the man with a bionic eye, played by the Mighty Boosh's Julian Barratt.

'It all started one night when I was listening to some Robyn Hitchcock that Julian had given me, and there was a track called "Detective Mindhorn",' says Simon Farnaby who has co-written the movie with Barratt. 'It just sounded like an 80s detective show to me, and I think the first pitch we did for the Mindhorn TV show was that it was "Bergerac meets the Six Million Dollar Man".' Farnaby is best known for his acting work with Barratt and Noel Fielding on The Mighty Boosh, as well as in Horrible Histories: when it came to creating a new comic character with Barratt, Mindhorn easily sprang to mind.

'It sounded like Kojak or Bergerac, and I love that kind of show,' notes Farnaby. 'The challenge was how do you make something new of it? I thought of Galaxy Quest and Three Amigos, and imagined there was a cat and mouse game with a criminal who wanted to match up against Mindhorn. The police have to bring in the actor (called Richard Thorncroft) to play the part again to catch the killer. Julian thought it would be fun if that actor was washed-up and was trying to manipulate that situation as a publicity thing. We knew that could be a great comedic engine for a film.'

As well as co-writing the script, Barratt and Farnaby play aging actor Thorncroft and his virile stunt-double Clive, respectively. 'I had to work out to play Clive,' says Farnaby. 'He needed to be buff. Julian says he had to eat a lot of curries to simulate Richard's paunch, but the truth is, that's just him.'

What Bergerac was to Jersey in the popular 80s BBC series, Mindhorn is to the Isle of Man, with a return to the island where his popular series was shot giving Thorncroft a chance at redemption.

'Of course, Bergerac was a big touchstone, and at one point we thought of getting John Nettles and setting it on Jersey, but that was too on-the-nose, so a producer suggested the Isle of Man,' recalls Farnaby. 'It had so many great locations: the Laxey Wheel, the caves, and that amazing sign that says "Electric Railways" which looks like a naff version of the Hollywood sign. Julian and I often do a running joke about actors who say "the location itself is a character", but in this case, it was true: the greatest actor here is The Isle of Man.'

It remains to be seen how the Isle of Man residents will react to Mindhorn, and the central character's references to their 'limited gene pool'. Farnaby is not too worried: 'I'm sure they'll be fine, they're very self-aware. Our taxi driver would pass through a village and say, "Oh, it's very Wicker Man down there". Which was fine by us, because The Wicker Man has some similarities to our story.'

But whether Mindhorn is a hit or not, Farnaby recently landed a role which should ensure he never gets washed-up like Richard Thorncroft: playing an X-Wing pilot in Star Wars prequel Rogue One should keep him in convention money for decades. 'When I got the offer, I asked "why me?" But there's a tradition of British actors playing X-Wing pilots; they're meant to be raggle-taggle rebels, so I suppose that's why they asked me … '

Mindhorn is on general release from Fri 5 May.